Chapter 10, Problem 10.22E

Though not strictly equivalent, there is a similar uncertainty relationship between the observables time and energy:

$\Delta E\cdot \Delta t\ge \frac{\hslash }{2}$

In emission spectroscopy, the width of the lines (which gives a measure of $\Delta E$) in a spectrum can be related to the lifetime (that is, $\Delta t$) of the excited state. If the width of a spectral line of a certain electronic transition is $1.00{\text{cm}}^{-1}$, what is the minimum uncertainty in the lifetime of the transition? Watch your units.